import middy from '@middy/core'
import { Options as MiddyOptions } from '@middy/util'
import { Context as LambdaContext } from 'aws-lambda'
import { SecretsManagerClient, SecretsManagerClientConfig } from '@aws-sdk/client-secrets-manager'

export type SecretType<T> = string & { __returnType?: T }
export declare function secret<T> (path: string): SecretType<T>

interface SecretsManagerOptions<AwsSecretsManagerClient = SecretsManagerClient>
  extends Omit<MiddyOptions<
  AwsSecretsManagerClient,
  SecretsManagerClientConfig
  >, 'fetchData'> {
  fetchData?: { [key: string]: string | SecretType<unknown> }
}

export type Context<TOptions extends SecretsManagerOptions | undefined> =
  TOptions extends { setToContext: true }
    ? TOptions extends { fetchData: infer TFetchData }
      ? LambdaContext & {
        [Key in keyof TFetchData]: TFetchData[Key] extends SecretType<infer T>
          ? T
          : unknown
      }
      : never
    : LambdaContext

export type Internal<TOptions extends SecretsManagerOptions | undefined> =
    TOptions extends SecretsManagerOptions
      ? TOptions extends { fetchData: infer TFetchData }
        ? {
            [Key in keyof TFetchData]: TFetchData[Key] extends SecretType<infer T>
              ? T
              : unknown
          }
        : {}
      : {}

declare function secretsManager<TOptions extends SecretsManagerOptions | undefined> (
  options?: TOptions
): middy.MiddlewareObj<unknown, any, Error, Context<TOptions>, Internal<TOptions>>

export default secretsManager